OO in Scheme

2011-04-26-SchemeOO.scm

;; All the OO stuff
(define (object selector-names . all-selectors)
  (define (apply-it selector selector-names selectors parameters)
    (cond ((null? selectors)                      '(I cant do that Dave!))
          ((equal? selector (car selector-names)) (apply (car selectors) parameters))
          (#t                                     (apply-it selector (cdr selector-names) (cdr selectors) parameters))))
  (lambda (selector . parameters)
    (apply-it selector selector-names all-selectors parameters)))

;; Defining a new object type
(define (person name age)
  (object '(name age)
          (lambda ()
            name)
          (lambda ()
            age)))

;; Usage
(define someone (person 'stu 28))
(someone 'name)
(someone 'age)

(define (maths)
  (object '(add)
          (lambda (a b)
            (+ a b))))
((maths) 'add 3 5)